The U.S. space agency, NASA, says inspections indicate that debris spotted near the space shuttle Atlantis has not damaged the craft's heat shields.

NASA officials say the shuttle has been cleared to return to earth on Thursday. They ordered the inspections after several pieces of debris were spotted floating near the craft.

Officials delayed the shuttle's return from Wednesday to give astronauts and engineers time to inspect the craft to make sure the objects did not break off the shuttle. The space agency said unfavorable weather conditions near the shuttle's landing site also contributed to the delay.

Had Atlantis been damaged, the crew might have had to conduct in-orbit repairs or return the shuttle to the International Space Station.

During its mission, the Atlantis crew successfully carried out three challenging spacewalks to install a pair of solar wings on the space station. It was the first construction mission since shuttle flights were grounded in 2003 after the shuttle Columbia broke apart upon re-entry, killing all seven astronauts on board.